Liquid hydrocarbons



United States Patent O 3,369,878 LIQUID HYDROCARBONS Paul Y. C. Gee, Woodbury, and Harry J. Andress, Jr., Pitman, N.J., assignors to Mobil Oil Corporation, a corporation of New York No Drawing. Continuation-impart of application Ser. No. 187,185, Apr. 13, 1962. This application Nov. 2, 1964, Ser. No. 408,353

21 Claims. (Cl. 44-73) This application is a continuation-in-part of our copending application Ser. No. 187,185, filed Apr. 13, 1962, now abandoned and also a continuation-in-part of our copending application Ser. No. 378,026, filed June 25, 1964, and relates to improved liquid hydrocarbons. In one of its aspects, this application relates more particularly to improved liquid hydrocarbons in the form of petroleum distillate hydrocarbon fractions. Still more particularly, in this aspect, the invention relates to improved liquid hydrocarbons in the form of non-lubricating distillate fuel oils which, in their uninhibited state, tend to form sediment and clog screens under the conditions of use.

It is Well known that liquid hydrocarbons in the form of fuel oils are prone to form sludge or sediment during periods of prolonged storage. This sediment has an adverse effect on burner operation, by reason of its tendency to clog screens and nozzles. In addition to sediment which is formed during storage, most fuel oils contain other impurities, such as rust, dirt and entrained water. Such sediment and impurities tend to settle out on equipment parts, such as nozzles, screens, filters, and the like, thereby causing clogging and failure of equipment.

A factor incident to the storage and handling of distillate fuels is the breathing of storage vessels. This re sults in the accumulation of considerable amounts of water in the tanks and presents the problem of rusting. Consequently, when the fuel is removed for transportation, suflicient water may be carried along to cause rusting of ferrous metal surfaces in pipelines, tankers, and the like.

Heretofore, in the case of fuel oils, it has been the practice to overcome the aforementioned difficulties through the use of a separate additive for each purpose, i.e., with a sediment inhibitor and an anti-screen clogging agent. The use of several additives, however, gives rise to problems of additive compatability, thus restricting the choice of additive combinations. In addition, of course, the use of a plurality of additives unduly increases the cost of fuel. It is, therefore, highly desirable, from a commercial standpoint, to overcome the aforementioned difiiculties through the use of a single additive agent, which is effective against sedimentationand screen and nozzle clogging.

Accordingly, it is an object of this invention to provide liquid hydrocarbons having improved properties.

Another object of the invention is to provide improved liquid hydrocarbons in the form of fuel oils containing a single additive which is adapted to inhibit sedimentation and prevent screen clogging.

Other objects and advantages inherent in the invention will become apparent to those skilled in the art from the following detailed description.

It has now been found that the aforementioned diflieulties, viz, sedimentation and screen clogging, can be overcome by the use of a single fuel oil addition agent. In this respect, it has now been found that distillate fuel oils containing minor amounts of the condensation reaction product of citric acid, certain tertiary-alkyl primary amines, alkylene polyamines and salicylaldehyde, are effectively inhibited, simultaneously, against all of the aforementioned difliculties.

The present invention, in general, provides improved liquid hydrocarbons, preferably in the form of non-lubri- 3,369,878 Patented Feb. 20, 1968 ice eating petroleum distillate hydrocarbons, containing from about 0.5 to about 200 pounds per thousand barrels of liquid hydrocarbon, of the condensation reaction product of citric acid, a tertiary-alkyl primary amine having from about 6 to about 30 carbon atoms with a tertiary-alkyl group attached to a nitrogen atom, an alkylene polyamine and salicylaldehyde. In these compositions the molar ratio of citric acid to each of the aforementioned tertiary-alkyl primary amine, alkylene polyamine and salicylaldehyde reactants varies from 1:1 to 1:2.

The addition agents contemplated herein, are produced by the condensation reaction of citric acid with the aforementioned tertiary-alkyl primary amine to form the corresponding citramic acid. Thereafter, the cit-ramic acid thus formed is subjected to a further condensation reaction with the alkylene polyamine to form the corresponding citramide. Finally, the citramide thus formed is subjected toa further condensation reaction with salicylaldehyde to form the corresponding salicylaldimine. The reactants are employed in accordance with the aforementioned molar ratios, and each condensation reaction is carried' out at a temperature varying between about C. and about 175 C.

The amines utilizable in forming the citric acid condensation product are tertiary-alkyl primary amines having from about 6' to about 30 carbon atoms per molecule, as indicated above, or mixtures of amines, in which the amino (NH group is attached to a tertiary carbon atom. These amines all contain the terminal group,

Non-limiting examples of such amine reactants are t-hexyl primary amine t-octyl primary amine, t-decyl primary amine, t-dodecyl primary amine, t-tetradecyl primary amine, t-octadecyl primary amine, t-eicosyl primary amine, t-docosyl primary amine, t-tetracosyl primary amine, and t-triacontyl primary amine.

The amine reactants can be prepared in several Ways, Well known to those skilled in the art. Specific methods of preparing the t-alkyl primary amines are disclosed in the Journal of Organic Chemistry, vol. 20, p. 295 et seq.

(1955). Mixtures of such amines can be made from a.

polyolefin fraction (e.g. polypropylene and polybutylene cuts) by first hydrating with sulfuric acid and water to the corresponding alcohol, converting the alcohol to alkyl chloride with dry hydrogen chloride, and finally condensing the chloride With ammonia, under pressure, to produce a t-alkyl primary amine mixture.

The alkylene polyamines that are employed for the condensation reaction with the citramic acid (produced by the aforementioned condensation reaction of citric acid and the t-alkyl primary amine) may comprise any alkylene polyamine, and, preferably, ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentarnine.

The liquid hydrocarbons that are improved in accordance with the present invention are those boiling from about 50 F. to about 750 F. Of particular importance are liquid hydrocarbons of the following types: liquid hydrocarbons comprising non-lubricating petroleum distillate fuel oils having an initial boiling point above gasoline and an end boiling point higher than about 600 F. and boiling substantially continuously throughout their distillation range; liquid hydrocarbons comprising petroleum distillate fuel oils boiling within the range from about 50 F. to about F., and which are normally subject to low temperature deterioration prior to being combusted; liquid hydrocarbons having an initial boiling point below about 350 F. and an end boiling point higher than about 600 F.; liquid hydrocarbons having an initial boiling point of at least 100 F. and an end boiling point higher than about 600 F.; and below about 350 F., and an end boiling point higher than about 600 F.

With respect to the term distillate fuel oils, it should be noted that this term is not intended to be restricted to straight-run distillate fractions. The distillate fuel oils can be straight-run distillate fuel oils, catalytically or thermally cracked (including hydrocracked) distillate fuel oils; or mixtures of straight-run distillate fuel oils, naphthas, and the like, with cracked distillate stocks. Moreover, such fuel oils can be treated in accordance with well known commercial methods, such as acid or caustic treatment, hydrogenation, solvent refining, clay treatment, and the like.

The distillate fuel oils are characterized by their relatively low viscosity, pour points and the like. The principal property which characterizes the contemplated hydrocarbons, however, is their distillation range. As hereinbefore described, this range will lie between about 100 F. and about 750 F. Obviously, the distillation range of each individual fuel oil will cover a narrower boiling range, falling, nevertheless, within the above-specified limits. Likewise, each fuel oil will boil substantially continuously throughout its distillation range.

Particularly contemplated among the fuel oils are Nos. 1, 2, and 3 fuel oils used in heating and as diesel fuel oils, and the jet combustion fuels. The domestic fuel oils generally conform to the specifications set forth in ASTM Specifications D396-48T. Specifications for diesel fuels are defined in ASTM Specifications D975- 48T. Typical jet fuels are defined in Military Specification MIL-F-5624B.

The amount of the aforementioned fuel stabilizer condensation Product that is added to the distillate fuel, in accordance with this invention, will depend, of course, upon the intended purpose and the particular condensation product selected, inasmuch as they are not all equivalent in their activity. Some may have to be used in greater concentrations than others to be effective. In most cases, in which it is desired to obtain all of the aforementioned beneficial results in fuel oil, namely, to inhibit sedimentation and to reduce screen clogging, additive concentrations varying between about pounds per thousand barrels of oil and about 200 pounds per thousand barrels of oil, will be employed. It may not always be desired, however, to accomplish all of the aforementioned results. In such cases, where it is desired to effect only one or two of such results, lower concentrations can be used. In general, therefore, the amount of the fuel stabilizer condensation product that can be added to the distillate fuel, in order to achieve a beneficial result, will vary from about 0.5 pound per thousand barrels of oil to about 200 pounds per thousand barrels of oil. Preferably, it will vary from about 10 to about 200 pounds per thousand barrels of oil.

If it is desired, the distillate fuel compositions of the present invention can contain other additives for the purpose of achieving other beneficial results. Thus, for example, there can be present such additional additives as foam inhibitors, ignition and burning quality improvers, scavengers and pre-ignition agents. Examples of such additives are silicones, dinitropropane, amyl nitrate, metal sulfonates, haloalkanes, phosphate esters, and the like.

The following specific examples are for the purpose of illustrating the novel fuel stabilizers and the distillate fuel compositions of this invention, and for exemplifying the specific nature thereof. It will be understood, of course, that the invention is not intended to be limited to the particular fuel stabilizers and fuels, or to the operations and manipulations described therein. Other fuel stabilizers and fuel compositions, as discussed hereinbefore, can be substituted, as those skilled in the art will readily appreciate.

The amine reactants used in the following examples are mixtures of pure amines. Amine A is a mixture of primary amines having a carbon atom of a tertiaryalkyl group attached to the amino (NI-I group and containing from about 12 to about 15 carbon atoms per amine molecule, and averaging about 12 carbon atoms per molecule. This mixture contains, by Weight, about percent tertiary dodecyl amine, about 10 percent tertiary pentadecyl amine, and relatively small amounts, i.e., less than about 5 percent, of amines having less than 12 or more than 15 carbon atoms. Amine B is a mixture of primary amines having a carbon atom of a tertiaryalkyl group attached to the amino (NH group and containing from about 18 to about 24 carbon atoms per amine molecule. This mixture contains, by weight, about 40 percent tertiary octadecyl amine, about 30 percent tertiary eicosyl amine, about 15 percent tertiary docosyl amine, about 10 percent tertiary tetracosyl amine, and relatively small amounts, i.e., less than about 5 percent of other amines as high as tertiary tricontyl amine.

EXAMPLE 1 A mixture of 105 grams (0.5 mole) of citric acid mono-v hydrate, 200 grams (1 mole) of Amine A, 100 cc., of xylene and 100 cc. of benzene was gradually heated to 150 C. with stirring to form the di-Amine A citramic acid, and was held at 150-155 C. until water stopped coming over. The amount of water collected was 28 cc., theory 27 cc. The resulting di-Amine A citramic acid was then diluted with 150 cc. of benzene. To the thus diluted di-Amine A citramic acid was then added gradually at room temperature with stirring 30 grams (0.5 mole) of ethylenediamine, followed by the addition of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was then refluxed at C. for a period of 2 hours, and then at 150 C. until water stopped coming over. The amount of 'water collected was 22 cc., theory 18 cc. The final product, which weighed 394 grams, theory 364 grams, contained 48 grams (12%) of xylene, and was clear and fluid at room temperature.

EXAMPLE 2 A mixture of 70 grams (Va mole) of citric acid monohydrate, 200 grams (Vs mole) of Amine B, 150 cc. of xylene and cc. of benzene was gradually heated to 165 C. with stirring to form the di-Amine B citramic acid, and was held at 165 C. until water stopped coming over. The amount of water collected was 19 cc., theory 18 cc. The resulting di-Amine B citramic acid was then diluted with cc. of benzene. To the thus diluted di- Amine B citramic acid was then added gradually at room temperature with stirring 20 grams /s mole) of ethylenediamine, followed by the addition of 40.7 grams /3 mole) of salicylaldehyde. The resulting mixture was then refluxed at 95 C. for a period of 2 hours, and then at 150 C. until water stopped coming over. The final product, which weighted 336 grams, theory 293 grams, contained 43 grams (13%) of xylene, and was clear and fluid at room temperature.

EXAMPLE 3 A mixture of 52.5 grams (0.25 mole) of citric acid, 50 grams (0.25 mole) of Amine A, 150 cc. of xylene and 100 cc. of benzene was gradually heated to 150 C. with stirring to form the mono-Amine A citramic acid, and was held at 150 C. until water stopped coming over. The resulting mono-Amine A citramic acid was then diluted with 150cc. of benzene. To the thus diluted mono-Amine A citramic acid was then added gradually at room temperature with stirring 30 grams (0.5 mole) of ethylenediamine, followed by the addition of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was then refluxed at 95 C. for a period of 2 hours and then at 150 C. until water stopped coming over. The final product, which weighted 188 grams, theory 162 grams, contained 26 grams (14%) of xylene and was clear and fluid when still warm.

EXAMPLE 4 A mixture of 52.5 grams (0.25 mole) of citric acid monohydrate, 79 grams (0.25 mole) of Amine B, 100 cc. of xylene and 150 cc. of benzene was gradually heated to 150 C. with stirring to form the mono-Amine B citramic acid, and was held at that temperature until water stopped coming over. The resulting mono-Amine B citramic acid was then diluted with 150 cc. of benzene. To the thus diluted mono-Amine B citramic acid was then added gradually at room temperature with stirring 30 grams (0.5 mole) of ethylenediamine, followed by the addition of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was then refluxed at 95 C. for a period of 2 hours, and then at 150 C. until water stopped coming over. The final product, which weighed 222 grams, theory 195 grams, containing 27 grams (12%) xylene, and was clear and fluid when still warm.

EXAMPLE 5 A mixture of 52.5 grams (0.25 mole) of citric acid, 50 grams (0.25 mole) of Amine A, 150 cc. of xylene and 50 cc. of benzene was refluxed at 130 C. to form the mono-Amine A citramic acid, and was held at 130 C. until water stopped coming over. To the resulting mono- Amine A citramic acid was then added gradually at room temperature with stirring 37 grams (0.5 mole) of propylenediamine, followed by the addition of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was then gradually heated to 140 C. and was held at that temperature until water stopped coming over. The final product, which weighed 274 grams, theory 170 grams, contained 104 grams (38%) xylene and was clear and fluid at room temperature.

EXAMPLE 6 A mixture of 52.5 grams (0.25 mole) of citric acid monohydrate, 75 grams (0.25 mole) of Amine B, 150 cc. of xylene and 50 cc. of benzene was refluxed at 130 C. to form the mono-Amine B citramic acid, and was held at that temperature until water stopped coming over. To the resulting mono-Amine B citramic acid was then added gradually at room temperature with stirring 37 grams (0.5 mole) of propylenediamine, followed by the addition of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was then gradually heated to 140 C., and was held at that temperature until water stopped coming over. The final product, which weighed 302 grams, theory 194 grams, contained 107 grams (35%) xylene and was clear and fluid at room temperature.

EXAMPLE 7 A mixture of 52.5 grams (0.25 mole) of citric acid monohydrate, 50 grams (0.25 mole) of Amine A, 150 cc. of xylene and 50 cc. of benzene was refluxed at 135 C. to form the mono-Amine A citramic acid, and was held at that temperature until water stopped coming over. To the mono-Amine A citramic acid thus produced was added gradually at room temperature with stirring 51.5 grams (0.5 mole) of diethylenetriamine, followed by the addition of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was then gradually heated to 145 C., and was held at that temperature until water stopped coming over. The final product, which weighed 250 grams, theory 188 grams, contained 62 grams (25%) xylene, and was clear and fluid at room temperature.

EXAMPLE 8 A mixture of 52.5 grams (0.25 mole) of citric acid monohydrate, 75 grams (0.25 mole) of Amine B, 150 cc. of xylene and 50cc. of benzene was refluxed at 135 C. to form the mono-Amine B citramic acid, and was held at that temperature until water stopped coming over. To the resulting mono-Amine B citramic acid was then added gradually at room temperature with stirring 51.5 grams (0.5 mole) of diethylenetriamine, followed by the addition 6 of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was then gradually heated to 150 C. and was held at that temperature until water stopped coming over. The final product, which weighed 293 grams, theory 208 grams, contained grams (29%) of xylene, and was clear and fluid at room temperature.

EXAMPLE 9 A mixture of 52.5 grams (0.25 mole) of citric acid monohydrate, 50 grams (0.25 mole) of Amine A and 150 cc. of xylene was refluxed at C. to form the mono-Amine A citramic acid, and was held at that temperature until water stopped coming over. To the resulting mono-Amine A citramic acid was added gradually at room temperature with stirring 73 grams (0.5 mole) of triethylenetetramine, followed by the addition of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was then gradually heated to C. and was held at that temperature until water stopped coming over. The final product, which weighed 268 grams, theory 209 grams, contained 59 grams (22%) of xylene, and was clear and fluid at room temperature.

EXAMPLE 10' A mixture of 52.5 grams (0.25 mole) of citric acid monohydrate, 75 grams (0.25 mole) of Amine B and 150 grams of xylene was refluxed at 145 C. to form the mono-Amine B citramic acid. To the resulting mono- Amine B citramic acid was then added gradually at room temperature with stirring 73 grams (0.5 mole) of triethylenetetramine followed by the addition of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was then gradually heated to 150 C. and was held at that temperature until water stopped coming over. The final product, which weighed 313 grams, theory 230 grams, contained 83 grams (27%) xylene, and was clear and fluid at room temperature.

EXAMPLE 11 A mixture of 52.5'\ grams (0.25 mole) of citric acid monohydrate, 50 grams (0.25 mole) of Amine A and 150 cc. of xylene was refluxed at 145 C. to form the mono-Amine A citramic acid, and was held at that temperature until water stopped coming over. To the resulting mono-Amine A citramic acid was then added gradually at room temperature with stirring 94.5 grams (0.5 mole) of tetraethylenepentamine followed by the addition of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was then gradually heated to 150 C. and was held at that temperature until water stopped coming over. The final product, which weighed 315 grams, theory 231 grams, contained 84 grams (27 xylene, and was clear and fluid at room temperature.

EXAMPLE 12 A mixture of 52.5 grams (0.25 mole) of citric acid monohydrate, 75 grams (0.25 mole) of Amine B and 200 cc. of xylene was refluxed at 145 C. to form the mono-Amine B citramic acid, and was held at that temperature until water stopped coming over. To the resulting mono-Amine B citramic acid was added gradually at room temperature with stirring 94.5 grams (0.5 mole) of tetraethylenepentamine, followed by the addition of 61 grams (0.5 mole) of salicylaldehyde. The resulting mixture was heated to 150 C. and was held at that temperature until water stopped coming over. The final product, which weighed 353 grams,,theory 256 grams, contained 97 grams (26%) of xylene, and was clear and fluid at room temperature.

Screen clogging The anti-screen clogging characteristics of a fuel oil were determined as follows: the test is conducted using a Sundstrand V3 or S1 home fuel oil burner pump with a self-contained 100-mesh Monel metal screen. About 0.005 percent, by weight, of naturally-formed fuel oil sediment, composed of fuel oil, water, dirt, rust, and organic sludge is mixed with 10 liters of the fuel oil. This mixture is circulated by the pump through the screen for 6 hours. Then, the sludge deposit on the screen is washed off with normal pentane and filtered through a tared Gooch crucible. After drying, the material in Gooch crucible is washed with a 50-50 (volume) acetonemethanol mixture. The total organic sediment is obtained by evaporating the pentane and the acetone-methanol filtrates. Drying and weighing the Gooch crucible yields the amount of inorganic sediment. The sum of the organic and inorganic deposits on the screen can be reported in milligrams recovered or converted into percent screen clogging.

EXAMPLE 13 Using a test fuel comprising a blend of 60 percent distillate stock obtained from continuous catalytic cracking and 40 percent straight-run distillate stock, and having a boiling range of between about 320 F. and about 640 F. (typical of No. 2 fuel oil), the additives described in Examples 1 through 12 were blended in portions of the test'fuel oil, and the blends were subjected to the Screen Clogging Test, as described above. The test results are set forth in Table I.

TABLE I Inhibitors Concn., lb./ Screen 1,000 bbls. Clogging,

percent Uninhibited fuel blend 100 Uninhibited fuel blend plus Ex. 1. 25 8 Uninhibited fuel blend plus Ex. 2- 50 2 Uninhibited fuel blend plus Ex. 3 50 32 Uninhibited fuel blend plus Ex. 4. 50 Uninhibited fuel blend plus Ex. 5- 25 29 Uninhibited fuel blend plus Ex. 6. 25 22 Uninhibited fuel blend plus Ex. 7. 25 44 Uninhibited fuel blend plus Ex. 9. 25 61 Uninhibited fuel blend plus Ex. 10. 50 12 Uninhibited fuel blend plus Ex. 11 60 Uninhibited fuel blend plus Ex. 12 37 It will be seen from Table I that the effect of the additives of the present invention upon the uninhibited fuel blend, have a pronounced effect in reducing screen clogging.

Sedimentation The test used to determine the sedimentation characteristics of fuel oils is the 110 F. Storage Test. In this test, a SOD-milliliter sample of the fuel oil under test is placed in a convected oven maintained at 110 F. for a period of 12 weeks. Then, the sample is removed from the oven and cooled. The cooled sample is filtered through a tared asbestos filter (Gooch crucible) to remove insoluble matter. The weight of such matter in milligrams is reported as the amount of sediment. A sample of the blank, uninhibited oil is run along with a fuel oil blend under test. The effectiveness of a fuel oil containing an inhibitor is determined by comparing the weight of sediment formed in the inhibited oil with that formed in the uninhibited oil.

EXAMPLE 14 The additives described in Examples 1 and 2 were blended in portions of the test fuel described in Example 13, and were subjected to the 1l0 F. Storage Test. The test results comparing the blended fuels and uninhibited fuels are set forth in Table II.

The efiicacy of the additives of the present invention in minimizing sedimentation in the aforementioned fuel oil blends, will be apparent from the data disclosed in Table II.

EXAMPLE 15 A similar storage test was performed with respect to the additives described in Examples 1 through 12, which were blended into a gasoline blend comprising percent catalytically cracked component, and boiling within the range from approximately 100 F. to approximately 400 F., as shown in Table III.

TABLE III Concn., ASTM Gum Inhibitors lb./l,000 Increase (after bbls. 16 Wks. at F.) mg./100 ml.

Uninhlbited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 3.0 Uninhibited gasoline plus 3 cc. TEL/gal.

%lus10.2 mg. Cu naphthenate/liter plus 5 2 3 x. Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 3. 0 Uninhibited gasoline plus 3 cc. TEL/gal. %lus20.2 mg. Cu naphthenate/liter plus x. Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu uaphthenate/liter 0 27. 6 Uninhibited gasoline plus 3 cc. TEL/gal. plus 0.2 mg. Cu naphthenate/liter plus Ex. 3 3 4.0 Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu nephthenate/liter 0 27. 6 Uninhibited gasoline plus 3 cc. TEL/gal.

%lus40.2 mg. Cu naphthenate/liter plus 5 4 4 x. Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 7. 3 Uninhibited gasoline plus 3 cc. TEL/gal. plus 0.2 mg. Cu naphthenate/liter plus Ex. 5 5 0.8 Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenatelliter 0 7. 3 Uninhibited gasoline plus 3 cc. TEL/gal.

1lus602 mg. Cu naphthenatelliter plus Uninhibi d gasoline plus 3 cc. a1.

plus 0.2 mg. Cu naphthenate/liter.- 0 7.3 Uninhibited gasoline plus 3 cc. TEL/gal.

%lus70.2 mg. Cu naphthenate/liter plus 5 0 9 x.

Uninhlbited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 7. 3 Uninhibited gasoline plus 3 cc. TEL/gal.

1us 0.2 mg. Cu naphthenate/liter plus 0 7 x. Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 14. 5 Uninhibited gasoline plus 3 cc. TEL/gal. :rlus 0.2 mg. Cu naphthenate/liter plus 1:. 9 10 1. 7 Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 l4. 5 Uninhibited gasoline plus 3 cc. TEL/gal. 1;E):lus18.2 mg. Cu naphthenate/liter plus X. Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 14. 5 Uninhibited gasoline plus 3 cc. TEL/gal. glus 0.2 mg. Cu naphthenate/liter plus x. 11 5 1.0 Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. 011 naphtheuatelliter 0 14. 5 Uninhibited gasoline plus 8 cc. TEL/gal. 15 32 mg. Cu naphthenatelliter plus x.

It will be seen from Table III above that a marked decrease in ASTM gum content is observed with respect to the aforementioned gasoline blend containing the specified additives, as compared, in each instance, with blends which are uninhibited.

9 EXAMPLE 16 A similar storage test was performed with respect to the additives described in Examples 1 through 12, which were blended into a gasoline blend comprising 100 percent catalytically cracked component, and boiling within the range from approximately 100 F. to approximately 400 F., and containing 3 cc. of tetra-ethyl lead per gallon and 0.2 mg. of copper naphthenate per liter of the uninhibited gasoline, as shown in Table IV.

TABLE IV Concn., ASTM Gum Inhibitors lb./l,000 Increase (after bbls. 16 wks. at 110 F.) mg./100 ml.

Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 17. Uninhibited gasoline plus 3 cc. TEL/gal. plus 0.2 mg. Cu naphthenate/liter plus Ex. 1 10 15.3 Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 118. 0 Uninhibited gasoline plus 3 cc. TEL/gal. plus 0.2 mg. Cu naphthenate/liter plus Ex. 3 9.3 Uninhiblted gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 118. 0 Unlnhibited gasoline plus 3 cc. TEL/gal. plus 0.2 mg. Cu naphthenatelliter plus Ex. 4 5 8.9 Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenatelliter 0 23. 9 Uninhibited gasoline plus 3 cc. TEL/gal. plus 0.2 mg. Cu naphthenate/liter plus Ex. 5 5 1.3 Uninhlbited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 23. 9 Unlnhibited gasoline plus 3 cc. TEL/gal.

,rlilusfiofl mg. Cu naphthenate/h'ter plus 5 1 6 x. Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphtlienate/liter 0 23. 9 Uninhibited gasoline plus 3 cc. TEL/gal. lus 0.2 mg. Cu naphthenate/liter plus x. 7 5 10.7 Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 23. 9 Uninhibited gasoline plus 3 cc. TEL/gal.

ipfllusgOZ mg. Cu naphthenate/liter plus 5 6 7 x. Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 21. 4 Uninhibited gasoline plus 3 cc. TEL/gal. plus 0.2 mg. Cu naphthenate/liter plus Ex. 9 10 8. 5 Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 21.4 Uninhibited gasoline plus 3 cc. TEL/gal. plus 0.2 mg. Cu naphthenate/liter plus Ex. 10 5 15. 2 Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 21. 4 Uninhibited gasoline plus 3 cc. TEL/gal. plus 0.2 mg. Cu naphthenate/liter plus Ex. 11 l0 5. 3 Uninhibited gasoline plus 3 cc. TEL/gal.

plus 0.2 mg. Cu naphthenate/liter 0 21. 4 Uninhibited gasoline plus 3 cc. TEL/gal. plus 0.2 mg. Cu uaphthenate/liter plus Ex. 12 10 6.4

It will similarly be seen from Table IV above that a marked decrease in ASTM gum content is observed with respect to the aforementioned gasoline blend containing the specified additives, as compared, in each instance, with blends which are uninhibited.

From the foregoing, it will be apparent that additive compositions of the present invention are markedly effective in inhibiting sedimentation and preventing screen clogging in liquid hydrocarbons, generally, and petroleum distillate fuels, in particular. Furthermore, although the present invention has been described with preferred embodiments, it will be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand.

We claim:

1. The method for preparing a fuel stabilizer which comprises: condensing citric acid and a tertiary-alkyl primary amine having fromv about 6 to about 30 carbon atoms with a tertiary-alkyl group attached to a nitrogen atom, to form the corresponding citramic acid; condens- 10 ing the citramic acid thus formed with an alkylene polyamine to form the corresponding citramide; and condensing the citramide thus formed with salicylaldehyde to form the corresponding salicylaldimine, the molar ratio of citric acid to each of said tertiary-alkyl primary amine, alkylene polyamine and salicylaldehyde reactants varying from 1:1 to 1:2.

2. The method of claim 1 wherein said tertiary-alkyl primary amine is present in a mixture of tertiary-alkyl primary amines having from about 12 to about 15 carbon atoms per amine molecule with a tertiary-alkyl group attached to a nitrogen atom.

3. The method of claim 1 wherein said tertiary-alkyl primary amine is present in a mixture of tertiary-alkyl primary amines having from about 18 to about 24 carbon atoms per amine molecule with a tertiary-alkyl group attached to a nitrogen atom.

4. The method of claim 1 wherein said alkylene polyamine is selected from the group consisting of ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

5. The fuel stabilizer prepared in accordance with the method of claim 1 wherein said tertiary-alkyl primary amine is present in a mixture of tertiary-alkyl primary amines having from about 12 to about 15 carbon atoms per amine molecule with a tertiary-alkyl group attached to a nitrogen atom.

6. The fuel stabilizer prepared in accordance with the method of claim 1 wherein said tertiary-alkyl primary amine is present in a mixture of tertiary-alkyl primary amines having from about 18 to about 24 carbon atoms per amine molecule with a tertiary-alkyl group attached to a nitrogen atom.

7. The fuel stabilizer prepared in accordance with the method of claim 1 wherein the alkylene polyamine is selected from the group consisting of ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

8. The method for preparing a fuel stabilizer which comprises: condensing citric acid and a tertiary-alkyl primary amine having from about 6 to about 30 carbon atoms with a tertiary-alkyl group attached to a nitrogen atom, to form the corresponding citramic acid; condensing the citramic acid thus formed with an alkylene polyamine to form the corresponding citramide; and condensing the citramide thus formed with salicylaldehyde to form the corresponding salicylaldimine, said condensation reactions being carried out at a temperature from about C. to about C. and the molar ratio of citric acid to each of said tertiary-alkyl primary'amine, alkylene polyamine and salicylaldehyde reactants varying from 1:1 to 1:2.

9. A liquid hydrocarbon, normally having a tendency to form sediment during storage, containing a stabilizing amount of the condensation reaction product prepared in accordance with the method of claim 1.

10. The composition of claim 9 wherein said condensation reaction product is present in an amount from about 0.5 to about 200 pounds per 1,000 barrels of liquid hydrocarbon.

11. The composition of claim 9 wherein said condensation reaction product is present in an amount from about 10 to about 200 pounds per 1,000 barrels of liquid hydrocarbon.

12. The composition of claim 9 wherein said tertiaryalkyl primary amine reactant is present in a mixture of tertiary-alkyl primary amines having from about 12 to about 15 carbon atoms per amine molecule with a tertiary-alkyl group atached to a nitrogen atom.

13. The composition of claim 9 wherein said tertiaryalkyl primary amine reactant is present in a mixture of tertiary-alkyl primary amines having from about 18 to about 24 carbon atoms per amine molecule with a tertiaryalkyl group attached to a nitrogen atom.

14. The composition of claim 9 wherein said alkylene polyamine reactant is selected from the group consisting of ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

15. The composition of claim 9 wherein the liquid hydrocarbon boils within the range from about 50 F. to about 750 F.

16. The composition of claim 9 wherein the liquid hydrocarbon comprises a petroleum distillate fuel oil having an initial boiling point above gasoline and an end boiling point higher than about 600 F. and boiling substantially continuously throughout its distillation range.

17. The composition of claim 9 wherein the liquid hydrocarbon comprises a petroleum distillate fuel oil boiling within the range from about 50 F. to about 150 F., and is normally subject to low temperature deterioration prior to being combusted.

18. The composition of claim 9 wherein the liquid hydrocarbon has an initial boiling point below about 350 F. and an end boiling point higher than about 600 F.

19. The composition of claim 9 wherein the liquid hydrocarbon has an initial boiling point of at least 100 F. and an end boiling point higher than about 600 F.

20. The composition of claim 9 wherein the liquid hydrocarbon has an initial boiling point from about 100 F. and below about 350 F., and an end boiling point higher than about 600 F.

21. The fuel stabilizer prepared in accordance with the method of claim 1.

References Cited UNITED STATES PATENTS 2,962,442 11/ 1960 Andress et al 4473 3,034,876 5/1962 Gee et a1 44-73 3,236,613 2/1966 Gee et a1 4471 DANIEL E. WYMAN, Primary Examiner. Y. M. HARRIS, Y. H. SMITH, Assistant Examiners. 

1. THE METHOD FOR PREPARING A FUEL STABILIZER WHICH COMPRISES: CONDENSING CITRIC ACID AND A TERTIARY-ALKYL PRIMARY AMINE HAVING FROM ABOUT 6 TO ABOUT 30 CARBON ATOMS WITH A TERTIARY-ALKYL GROUP ATTACHED TO A NITROGEN ATOMS, TO FORM THE CORRESPONDING CITRAMIC ACID; CONDENSING THE CITRAMIC ACID THUS FORMED WITH AN ALKYLENE POLYAMINE TO FORM THE CORRESPONDING CITRAMIDE; AND CONDENSING THE CITRAMIDE THUS FORMED WITH SALICYLALDEHYDE TO FORM THE CORRESPONDING SALICYLALDIMINE, THE MOLAR RATIO OF CITRIC ACID TO EACH OF SAID TERTIARY-ALKYL PRIMARY AMINE, ALKYLENE POLYAMINE AND SALICYLALDENHYDE REACTANTS VARYING FROM 1:1 TO 1:2.
 9. A LIQUID HYDROCARBON, NORNALLY HAVING A TENDENCY TO FORM SEDIMENT DURING STORAGE, CONTAINING A STABILIZING AMOUNT OF THE CONDENSATION REACTION PRODUCT PREPARED IN ACCORDANCE WITH THE METHOD OF CLAIM
 1. 